The present invention relates to a process for producing a chassis for holding the body and engine of an automotive vehicle, and more particularly, to a process for producing such chassis of aluminum. The aluminum herein includes pure aluminum and aluminum alloys.
There are many kinds of chassis known in the art, but in common with them, they comprise a frame made of steel bars welded to each other. The known process consists of several steps starting with the framing of steel bars and ending with the welding of them. Thus the process is time- and labor-consuming, which reflects in the production cost. Another disadvantage is that the steel frame is heavy, which is contrary to the modern trend of lightweight vehicles. In addition, the frame has many welded seams, which are liable to fracture during use.
In line with the modern demand for lightweight vehicles there are various proposals among which is a chassisless or a monocoque. The chassisless may be effective for some types of vehicles; however, for other types requiring a rigid body a chassis is nevertheless indispensable.
One proposal for lightweight vehicles is to use a chassis made of light material such as aluminum and plastic. Nevertheless, plastic is at a premature stage for use in chassis, and aluminum is considered as a last resort to achieve chassis in the age of lightweight vehicles. It has been found, however, that the mere substitution of aluminum for steel does not solve the problem, and that there should be a new process for using aluminum instead of steel.
The present invention is to provide a process adapted for producing chassis of aluminum which overcomes the difficulties arising from the substitution of aluminum for steel.
Other objects and advantages of the present invention will become more apparent from the following detailed description, when taken in conjunction with the accompanying drawings which show, for the purpose of illustration only, one embodiment in accordance with the present invention.
According to the present invention, there is provided a process for producing a chassis for vehicles, the process including the steps of fabricating a single frame element of aluminum alloy, the frame element having an upper beam, a lower beam and a web portion connecting between the two beams, removing some of the web portion to a desired length, pulling the upper beam and lower beam of the web vacant portion in opposite directions so that the web vacant portion becomes an expanded opening, bending the frame element in accordance with the size and shape of the body of a vehicle to be placed on the chassis, and welding the terminating ends of the frame element to form an endless frame.